This animation explains how storm surges can inundate Bangladesh's low elevation territory.
Bangladesh evacuated hundreds of thousands of people to higher ground ahead of Tropical Cyclone Mahasen. Bangladesh's low elevation puts large areas of the country at risk of flooding in the event of a storm surge. Low pressure under the storm carries the surge along until it makes landfall. Around 14% of Bangladesh's population lives on land under five meters in elevation. Bangladesh's Great Bhola Cyclone in 1970 had a 10 meter storm surge. Land in the Ganges Delta is fertilized by annual flooding. Bangladesh suffers 53% of the world's cyclone fatalities, even though only 1% of cyclones strike there.